660804349440 has 160 divisors (see below), whose sum is σ = 2112966725760. Its totient is φ = 176176308224.

The previous prime is 660804349397. The next prime is 660804349511. The reversal of 660804349440 is 44943408066.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 660804349440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64407031 + ... + 64417289.

It is an arithmetic number, because the mean of its divisors is an integer number (13206042036).

Almost surely, 2^660804349440 is an apocalyptic number.

660804349440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 660804349440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1056483362880).

660804349440 is an abundant number, since it is smaller than the sum of its proper divisors (1452162376320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

660804349440 is a wasteful number, since it uses less digits than its factorization.

660804349440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18672 (or 18656 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 48.

The spelling of 660804349440 in words is "six hundred sixty billion, eight hundred four million, three hundred forty-nine thousand, four hundred forty".